Quisiera un café con leche, por favor I'd like a coffee with milk, please

Ordering politely: quiero and quisiera. Quiero un bocadillo de jamón means "I want a ham sandwich": direct, and perfectly normal. Yo quisiera un café con leche means "I'd like a coffee with milk": more polite, and this is how you talk to a waiter. Both come from querer (to want). Quisiera follows a rule you'll learn much later (the stem quis- and the ending -iera), so for now just learn it as a ready-made word.

Asking: ¿Me trae…? ¿Me trae un vaso de agua, por favor? and ¿Nos trae la cuenta, por favor? Trae comes from traer (to bring): present tense, usted form, because you speak to a waiter formally. Word for word it's "You bring me…?": you ask with a question, not a command. Me and nos mean "me" and "us". The same goes for ¿Me pone otra, por favor?: pone comes from poner (to put, to serve), and otra means "another one" (another cerveza). Don't put una before otra.

What's in it: de jamón, de chocolate. Un bocadillo de jamón is a ham sandwich, un helado de chocolate is a chocolate ice cream: Spanish names the filling or the flavor with de after the noun, where English puts the word first. But it's un café con leche with con (with), because the milk is added to the coffee.

está caliente, está fría. El café está muy caliente, mi cerveza está muy fría: to say what a dish or a drink is like right now (hot, cold), use estar.

son catorce euros, Aquí tiene. The total is said with son: son catorce euros (that's fourteen euros). Aquí tiene means "here you go": you say it when you hand something over. In Pago yo, the yo at the end adds weight: "I'm paying, not you."